A DC-DC converter generally converts a direct current from a first voltage level and current level to a second voltage and current level. For example, a step-down DC-DC converter can convert a voltage input (Vin) of 12V at 10 Amps to a voltage output (Vout) of 1.2V approximately at 100 Amps. For a more specific example, a two-phase DC-DC converter can include a pulse width modulator (also simply referred to as a modulator) that includes a first pulse width modulated output (PWM lout) and a second PWM output (PWM2out). The signals output at PWM1out and PWM2out, which can also be referred to as the PMW1out signal and the PWM2out signal, are 180 degrees out of phase. In other words, the PWM2out signal lags (or leads) the PWM1out signal by 180 degrees.
Conventionally, these 180 degrees out of phase signals output by PWM1out and PWM2out directly drive a pair of Driver-MOSFET stages, which can be referred to as DrMOS1 and DrMOS2. The DrMOS1 can be considered to be part of a first channel of the two-phase DC-DC converter, and the DrMOS2 can be considered to be part of a second channel of the two-phase DC-DC converter.
The voltage level output by the DC-DC converter is preferably a regulated voltage level having a relatively tight tolerance (e.g., +/−1%). Further, it is preferred that the two channels of the two-phase DC-DC converter are generally balanced, i.e., each channel handles generally approximately the same amount of power and current, so that one of the two channels is not damaged due to handing too much power and current. However, high frequency load transient events can undesirably affect such a balance between the channels, both adversely affecting the voltage produced by the two-phase DC-DC converter, as well as potentially damaging components within the DC-DC converter. Such high frequency load transient conditions may occur, e.g., when the one or more loads (e.g., a CPU) connected to the voltage outputs for the DC-DC converter power on after previously being powered off, or alternates between a high power operating state (e.g. operating at maximum clock frequency) and a low power operating state (e.g. sleep mode or stand by mode) with relatively high frequency, but are not limited thereto.
A DC-DC converter may experience a fault, e.g., because an inductor and/or a Driver-MOSFET stage, or a portion thereof, is missing, fails, is connected incorrectly, or becomes disconnected. Such faults, if not handled correctly, can cause damage to a DC-DC converter, as well as the larger circuit within which the DC-DC converter is connected.